Drawbench carriage



May 1, 1951 s. w. GARWIG DRAW BENCH CARRIAGE 3 Sheets-Sheet 1 Filed Dec. 2, l946 INVENTOR. N 4. smv w. 439M104 BY M *M May 1, 1951 G. w. GARWIG DRAW BENCH CARRIAGE 3 Sheets-Sheet 2 Filed Dec. 2, 1946 INVENTOR GLENN W G EN/5 y 1, 1951 G. w. GARWIG 2,551,260

DRAW BENCH CARRIAGE Filed Dec. 2, 1946 3 Sheets-Sheet 5 Patented May 1, 1951 UNITED STATES PATENT OFFICE 2,551,260 DRAWBENCH CARRIAGE Glenn W. arwigi Youngstbwn Ohio, assigiibr to The Aetna-Standard Engineering Company, Youngstown, Ohio; a corporation ofOhi'o Ap liance December 2, 1946, serial No; 713,439

2 Claims.

I This invention relates to draw benches of the type used in the manufacture of tubes, bars, rods, etc., and more particularly to an improved draw bench carriage and gripper mechanism.

In the manufacture of drawn tubes (it being understood that where the term tube" is used herein it is intended to include bars, rods, and the like) it is customary to provide an elongated draw bench having at one end a die'stand which supports the die ordies through which the tubes being handled are drawn. A carriage is mounted on the draw bench bed or trackway and is movable by suitable means along the trackway toward and away from the die stand. In operation the ends of the tubes being drawn are pushed through the dies and the projecting ends gripped by jaws mounted on the carriage so that, when the carriage is moved away from the die stand, the tubes will be drawn through the die and the desired're duct'ion imparted thereto.

In my copending United States Patent Application Serial No. 599 185, filed June 13, 1945; and now Patent No. 2,536,637, granted Jan. 2, 1951, I have described and claimed an improved draw bench arrangement having a self-propelled car riage which is driven along the trackway by pinion gears mounted on the carriage and engaging racks which extend lengthwise of the bed or trackway. Prior to the development of the an parat'us of my said cope n'ding United States'patent application it was customary and convention al to provide a heavy chain, having its upper reachmovable away from the die stand, and adapted to be engaged by a hook mounted on the carriage. Independent cable means were usually employed with this tvpeof apparatus toreturn the carriage to the die-stand.

The present invention relates to an improved carriage and a gripper head which is particularly adapted for use with the self-propelled type of draw bench carriage 'disclosedin my above noted ccpending patent applicationbut which, as will be understood by those skilled in the art, may also advantageously" be used with the old style chain and cable operated draw bench carriage.

I In the operation of draw benches of the type to" which this invention pertains the carriage is returned to a position adjacent the die after each drawing operation. In theusualdraw bench" arrangementth'e return stroke of the carri'age involves wasted time as no drawing is being done during this'operation; achcorclingly the carriage is returned as rapidly as po'ssibl'e and means are" provided whic h' are intended to stop the draw bench carriage wh'e'n' the' gripper seas isadfa cent to or just engaging the stand. in actual operation ai's' punq that the gri head end of the carriage frequently engages he die stand with con rable impact. As tli riag'es are quite heavy and have consid momentum, the sudden stopping u on triking the die stand places a substantial shock load than the carriage structure. This is undesirab e' in any type of draw bench carriage arrangement but particularly soin the selfpropelled type of ear: ria'ge described and claimed in my beve mentioned patent application in" which the d met-6r is mounted on the carriage with its shalt in horizontal position. 'Ifhis motor be, quite large to; furnishsufiic'ient pdwer' fer; 't 1 drawing operations arid accordingly must have a relativelyheavyarffiature; shaft, etc; The shock load imposed uporjr the motor bearings; and are bearings of the other parts of the carriage drive mechanism, due tdinipadt of the carriage with th'di'e stand may at times be severe and cordingly may cause damage to the thrust bear ings of the motor" shaft and associated parts. n

It is therefore an object of my present revere tion to provide means for absorbing the impact was or shock which occurs when the riep rhgq end of i draw bench carriage strikes the di stand. p

other obiects or my invention include: the o; visionof a unitary'gripper' head assembly which is" resiliently rnoiinte'd on 'a draw henchcarriage whereby limited shock absorbin movement of the gripper head relative to the main frame 0f the teenage is permitted upon impact of the gribper head with the die stand the provision of an mprovedl gripper head con truction for draw' bench carriages" which in" addition to its usual stock gripping funct b'ns also serves-as a shock absorber orre'silierit bumper for the draw' bench car fa without in aim; was; interferin w th the effect e operation of the err-seer head'in' firmly and postmay rinnin the ends of the arms as they egrtend throu h the d or dies in the die stand? th provision of ashock se n-m air-inner head f'or draw bench carriages which is adan'te'd to be with either the" old style hook chain and cable operated carriages or with the self-propelled motor driven carriages of. the type shown in my previously referred to copen'ding United States patent application, and which is also adaptedito be used with; carriages having gripper heads at each end for usewi'thdouble actin' 'draw benches in' which die stands are provided at both ends of the bench and a drawing operation tak es 'place 3 during each movement of the carriage along the bench; and, the provision of a rugged, simple, fully automatic shock absorbing gripper head for draw bench carriages which will stand up under severe usage and which requires a minimum of care and maintenance in use.

The above and other objects of my invention will appear from the following description of a preferred form thereof reference being had to the accompanying drawings in which:

a rees Figure 1 is a plan view of a self-propelled draw I bench carriage incorporating my improved gripper head, portions of the supporting trackways being shown together with a portion of the die stand, the carriage being illustrated in position with the gripper head engaging the die stand and the resilient support for the gripper head being shown in cross-section.

Figure 2 is a side elevation of the apparatus shown in Figure 1, the gripper head mechanism and ide stand being shownin vertical cross-section taken substantially on line 2-2 of Figure 1. 1 Figure 3 is an enlarged vertical cross-sectional view taken on line 33 of Figure 1.

Figure 4 is a horizontal cross-sectional view taken on line 4-4 of Figure 3 but illustrating the gripper head assembly only. Figure 5 is a vertical cross-sectional view of the apparatus shown in Figure 4, taken on line 5 5 of Figure 3;- v v Figure. 6.is a front elevation, looking into the gripping jaws, of the gripper head shown in Figures4 and 5, the jaws being in open or released position. y Figure 7 i a fragmentary side elevation of the gripper head shown in Figures 4, 5, and 6. .,.As.has previously been pointed out, my shock absorbing gripper head is particularly advantageous for use with. the self-propelled draw bench carriage disclosed and claimed in my above noted copending United States patent application and accordingly I haveshown and will describe herein .my improved gripper head as em.- bodied ina draw bench carriage of this general type. -Referring to Figures, 1 and-2, the draw menchcarriage comprises a main frame structuregenerally indicated at F. Supporting. wheels I, 2, 3, and 4 are mounted on the frame Fand run on .the spaced trackways 5 and 6. The inner facesof-tracks 5 and 6 are, provided with racks land 8 which are engaged by drive pinions 9 and ,HI respectively. These pinions aremounted on ,vertical shafts, .one of which is seen at in .Figure 2, the upper end of. this shafthaving a bearing in the housing. l2 and the lower end carrying a suitable worm gear 13 whichis en- .closedin the housing l4. vA corresponding worm gear 15 ismounted on the verticalshaft of pinion ,landis enclosed in a. housing l6. A worm engages bothof the worm gears l4 and I5 and is mounted on a shaft H! which is supported in suitable bearings in .the carriage frame F. Shaft |8 .is.c,oupled to theprojecting shaft 9 of the reversibledrive motor which is also mounted on and carriedbv the frame F. Thus, when the motor 20 rotates in onedirection the pinions 9 Land l0, acting through the racks and 8, will advance the carriage toward the die stand S and 'when the motor is rotated in the opposite direction the carriage will be moved away from the die stand to draw the tubes through the dies 2|.

" The forward end of the frame F is formed as a generally tubular support and housing 22 for the gripper head assembly G. This gripper head assembly includes a main body member 23 the rear 4 portion of which 24 (see Figure 5) is cylindrical and has a Sliding fit within the inner bore of the tubular end portion 22 of the carriage frame F. Circumferentially spaced slots or key ways 25 are formed in the outer surface of the body 23 and keys or guide members 26 extend radially inwardly from the retaining ring 21 into the slots 26. A circumferentially extending shoulder 28 on the body 23 is adapted to engage the remaining ring 21 and limit the forward movement of the gripper head G relative to the carriage frame F, it being understood that the retaining ring 21 will be secured to the end of the tubular portion 22 of the frame'F by suitable screws or the like. A shoulder 29 projects inwardly from the inner bearing surface of the tubular portion 22 of the frame F and, as is clearly seen in Figures 1 and 2, may act as a stop to prevent excessive inward movement of the gripper head G relative to the frame F.

. In Figures 1 and 2 the gripper head G is shown in its forward or fully extended position with the shoulder 28 engaging the retaining ring 21. Sufficient clearance is provided between the inner end face 30 of the body 23 and the shoulder 29 so that under normal conditions of operation the body 23 will not strike the shoulder 29. From the above description it will be seen that the gripper head G is mounted for limited sliding movement in the frame F, being restricted in its forward movement by the retaining ring 2'! and in its rearward movement by the shoulder 29 and being prevented from relative rotary movement in the supporting sleeve 22 by the keys 26 which extend into the key ways 25.

In order to provide a resilient backing for the slidable gripper head G a group of four relatively heavy coil-springs 3|, 32, 33 and 34 are disposed symmetrically around the longitudinal center line of the gripper head G and are maintained under initial compression, one end of each spring abutting against the body 23 of the gripper head and the other end of each spring abutting against, and being disposed in shallow bores in, atransverse web 35 which is an integral part of the carriage frame F. The springs 3|, 32, 33 and 34 extend into and are partially housed in the bores 3|, 32', 33 and 34' in the gripper head body 23. r

Thus the gripper head G is normally urged into its. forward position as shown in Figures 1 and 2 by the springs 3|, 32, 33 and 34. However, if and when the nose portions 36 and 31 of the body 23 strike the die stand S these springs will be compressed permitting the main carriage structure to advance toward the die stand under the resilient snubbing action of the springs thus cushioning the impact with the die stand and preventing the transmission of harmful shock loads to the carriage drive mechanism, etc.

The arrangement of the tube gripping jaws in the gripper head G may be of any suitable type but I have illustrated herein an assembly of jaws andjaw operating elements which are particu larly well suited to be contained within the gripper head body 23 and to be entirely independent of the rest of the carriage structure. The nose portion of the body 23 is formed with a transversely extending opening having con;- verging inner surfaces 38 and 39. The illustrated gripperhead is provided with three pairs of grip-.- ping jaws, which are generally indicated at J, J and J" in Figure 6, and thus is adapted to grip and draw three tubes or bars simultaneously. As the 'pairs of gripper jaws are substantially Y alike in arrangement and mode ofoperation only the center set or pair, Jwill be-described in detail. r

This center pair of jaws J includes sliding jaw holders 4B and 4| supported for movement relative to the faces 38 and 39 of the body 23b'y a bottom pair of guide plates 42-43 and a top pair of guide plates 44-45 which aresupported parallel to but spaced from the faces -38 and by brackets 46, 41, 48 and 49. Thus the jaw holders 46 and 4|, which have outwardly extending flanges on their upper edges, are held in position to have guided sliding movement on the surfaces 38. and 39 respectively. Jaw teeth are formed on detachable members v|] which are clamped in position on the inner faces of the jaw holders 40 and 4| as is clearly seen in Figure 5.

When the jaw holders and 4| are retracted as shown in Figure 5 the jaws; are opened to receive the end of a tube or bar. When the jaw holders slide forward relative to the body 23 into the dot and dash line positions shown in Figure 5 they also move inwardly toward each other and cause the gripping action to take place. The

three sets of Sliding jaw holders are simultaneously operated by means of an equalizer bar 5| which extends across the transverse opening in the body 23 through slots 5! in the jaw holders (see Figures 4 and 5). Spring backed balls 52 are carried by the bar 5| on its front face and engage the forward sides of the slots 5| in the jaw holders (Figure 5 showing this engagement in jaw holders 40 and 4|) to permit equalizing action between the individual sets of jaws in case the diameters of the three tubes being gripped are not exactly the same. The rear face of bar 5| engages the opposite sides of slots 5| and thus any movement of bar 5| is transmitted to each of the jaw holders.

A pair of rods 53 and 54 have threaded connection with the bar 5| at their forward ends and extend through and have bearings in the web 55 of the body 23. The rear ends of the rods 53 and 54 are secured to a rigid yoke member 56 (see Figures 4 and 5). This yoke extends upwardly and is connected by means of a pin 51 to an operating rod 58 which extends forwardly through the body 23 and is provided with a bearing at 59. A spring 6|) surrounds the operating rod 58 and engages the body 23 at its forward end i and the yoke 56 at its opposite end. This spring tends to move the yoke 56 to the right (Figures 2 and 5) and, as the yoke is connected to the rods 53 and 54 which are in turn connected to the equalizer bar 5|, the spring 50 tends to hold the center pair of jaw holders, 404|, together with the two end pairs of jaws J and J, in retracted or open position as seen in Figure 5.

The outer or forward end of the operating rod 58 is tapered at 6| to facilitate its entry into a sleeve 62 mounted in the die stand S. On the side of rod 58 adjacent its outer end a notch 63 is formed which is adapted to be engaged by a spring backed plunger 64 mounted in the die stand and projecting a limited distance into the sleeve 62.

As is seen in Figure 1, the notch 63 and the plunger 64 are so shaped that when the carriage and the gripper head G approach the die stand S the operating rod 58 will enter the sleeve 62, the plunger 64 will be initially pushed back by the end of rod 58 and then will snap into notch 63 as seen in Figure 1. As illustrated in Figure 2, the jaws of the gripper head are all held in retracted or open position by the spring 60.

1waeaaaanaa is startedawa'y-fr'om theme stand 8- on its-drawing stroke the ripper head G moves positively with the carriage frame F because of the engagement of the shoulder -28 on the body 23 with the retaining ring 21. However the engagement of the plunger 64 in the notch 63 is sufficiently strong, and the faces of the notch '63 are so shaped, that as the body 23 moves away from the die stand S the rod 58 and its associated parts, including the pair of jaw holders 4!] and 4| and their law members 56, remain stationary. This relative movement between the body 23 and the jaw holders 40 and 4| causes the jaw holders and jaws to be moved inwardly and to grip the end-of the tube'whic'h' has previously been pushed through the die aperture 65. When the jaws 50 grip the stock further relative-movement between the jaw holders 404| and the body 23 is prevented and the operating rod 58 will be pulled loose from the bushing 52. As the carriage continues to move away from the die stand Sthe drawing resistance of the tubes will maintain the grip or bite of the jaws.

In order to provide means for manually operating the gripper jaws independently of the operating rod 58 I provide a cam finger 66 which is secured to a transverse shaft 61 rotatably supported in flanges 68 on the main carriage frame F (see Figure 3). An operating handle 69 is secured to one end of the shaft 6'! and if for any reason it is desired to move the jaws into gripping position independently of the action of the operating rod 58, the operator merely turns the shaft 61 in counter-clockwise direction as shown in Figure 2 causing the cam finger 66 to engage the yoke 56 and push it forward against the action of the spring 6|]. This operation will move the gripping jaws together in the manner previously described. As the shaft 61 is mounted in the carriage frame F it is necessary to provide slots Ill in the rear portion 24 of the body 23 to permit sliding movement of the gripper head assembly in the frame F.

From the above description it will be seen that the automatic gripping action of the gripper head upon movement of the carriage away from the die stand is not in any way affected or interfered with by the shock absorbing relative movement of the gripper head body 23 and the frame F caused by impact with the die stand. If the nose of the gripper head strikes the die stand with considerable force the frame -F will continue to move toward the die stand, compressing the shock absorbing springs 3|, 32, 33 and 34. After compression the springs will expand and will tend to move the frame F away from the die stand. By providing a completely integral and self-contained gripper head unit which is entirely independent of the carriage frame F and is spring mounted thereon I have provided an effective shock absorbing means for the draw bench carriage assembly while main taining the advantages and mode of operation of the gripper head. By mounting another gripper head G on the opposite end of the carriage frame F in similar manner a double ended carriage may readily be constructed.

Although I have described the illustrated embodiment of my invention in considerable detail it will be understood by those skilled in the art that variations and modifications may be made in the form and arrangement of my apparatus without departing from the spirit of my invention. I do not therefore wish to be limited to the exact structure herein shown and described but claim as my invention all embodiments thereof coming within the scope of the appended claims.

I claim:

1. In a draw bench carriage, a frame structure, a gripper head supported for movement relative to said frame structure and projecting from one end thereof, gripping jaws carried by said gripper head and movable relative thereto between gripping and retracted positions, and resilient shock absorbing means interposed between said gripper head and said carriage for resisting movement of said gripper head toward said frame structure.

2. In a draw bench carriage, a carriage frame structure having a hollow end portion, a gripper head disposed in said hollow end portion, guide means interposed between said gripper head and said frame structure for guiding said gripper head in movement relative to said frame structure substantially parallel to the direction of travel of said carriage, stop means on said frame structure to limit movement of said gripper head relative thereto, spring means disposed in said hollow end portion between said frame structure and said gripper head and urging said gripper head away from said frame structure and cushioning movement between said gripper head and said frame, and gripping jaws carried by said gripper head.

GLENN W. GARWIG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED 'STATES PATENTS Number Name Date 7 2,003,645 Dalton June 4, 1935 2,275,573 Sturm Mar. 10, 1942 2,344,293 Evans Mar. 14, 1944 

